Chemical Stability and Oxygen Permeability of La[sub 0.4]Ba[sub 0.6]Fe[sub 1−x]Zn[sub x]O[sub 3−δ] Perovskite: The Effects of Zn Substitution

Perovskite oxide, (LBF), is a typical cobalt-free, mixed ionic–electronic conductor. This work explored B-site doping in LBF by partially substituting iron with Zn, which results in . An investigation on the effects of Zn doping was then conducted. The introduction of Zn in largely augments the concentration of oxygen lattice vacancies and the chemical resistance against reduction in the atmosphere. This conclusion was drawn from the results of X-ray diffraction and temperature-programmed reduction. Furthermore, the temperature-programmed desorption showed us that lattice oxygen desorption is affected by the vacancy concentration and the amount of movable lattice oxygen. The oxygen permeability of the membrane increased from 800 to , with increasing -doping extent ( -value) from 0 to 0.1, but the improvement discontinued with further increase in the value from 0.1 to 0.2, namely both ( and 0.2) membranes presented the same oxygen permeation flux as high as at . Nevertheless, perovskite with exhibited superior chemical stability in reducing atmosphere at over that with .